The Predaceous Diving Beetle is a 'tiger' among the underwater larval insect world. Adults don't mind a little time on land either.
Predaceous Diving Beetle Videos
Predaceous Diving Beetles swimming and floating
Resting on underwater plants
Found in or near large ponds and lakes, the Predaceous Diving Beetle is hydrodynamic for a life mostly spent in water. It may look like it only has two front legs, but the other 4 legs are there and underneath it. The back legs are flat and used to propel it forward water. The front legs look like bent 'arms' with feathery hairs on all legs.
They feed on other aquatic insects and creatures, including small tadpoles. Males use their paddle-like feet to secure the female for mating. Both genders fly very well out of water and are attracted to lights at night. They are most active at night and can be seen moving from one water source to another (puddles, pools, ponds, flooded roads, etc.)
Larvae hatch underwater and look somewhat like long, tubular naiads (larval dragonflies) or centipedes (minus all but 6 legs). They have what appear to be pincers at the mouth which are likely used to catch and consume aquatic insects. They are ferocious predators and aggressive by nature.
Scientific Name: Cybister fimbriolatus
Size (Adult; Length): 26mm to 34mm (1.01in to 1.33in)
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Antennae: Beetles have a pair of antennae on the head used as sensors.
Head: The head is home to the insect's eyes, antennae, and mandibles (jaws).
Thorax: Holds the three pairs of legs as well as vital internal organs.
Elytron: One of two wing cases on a Beetle that protects its wings (plural: elytra).
Wings: Appendages used for flying and kept under the elytra until needed.
Abdomen: Houses organs related to circulation, reproduction, and excretion.
Legs: Beetles have three pairs of legs located at the thorax, numbering six legs in all.